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Where is the innovation?

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The 2009 MySQL Conference has closed it’s submissions for papers. This year the motto is “Innovation Everywhere”.

Last weekend’s Open SQL Camp in Charlottesville, Virginia, we had the chance to talk about the movements in the MySQL ecosystem. I was impressed to get the details of the Percona MySQL Patches, but focus is still in 5.0. (Welcome to the Percona team Tom Basil) Our Delta is attempting now to integrate patches into various MySQL branches. There was an opening keynote by Brian Aker from Drizzle, and Drizzle team Jay Pipes and Stewart Smith on hand. It was also announced that MySQL 5.1.30 will be GA, available in early December.

But these are not innovations that are ground breaking. Last year, it was the announcement of KickFire that I found most intriguing regarding innovation.

What is there this year?. The most interesting thing I read last week was Memcached as a L2 Cache for Innodb – The Waffle Grid Project. This is my kind of innovation. It’s sufficiently MySQL, but just adds another dimension with another companion technology. The patch seems relatively simple in concept and code size, and I’m almost prepared to fire up a few EC2’s to take this one for a spin. I’m doubly impressed because the creators are two friends and colleagues that are not hard core kernel hackers, but professionals on the front line dealing with clients daily. Will it be successful, or viable? That is the question about innovation.

Unfortunately I spend more time these days not seeing innovation in MySQL, but in other alternative database solutions in general. Projects like Clustrix, Inc., LucidDB, and Mongo in the 10gen stack.

When mysqldump –no-set-names matters

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I had this perplexing problem yesterday where a mysql dump and restore was producing different results when using MaatKit mk-table-checksum.

mk-table-checksum --algorithm=BIT_XOR h=192.168.X.XX,u=user,p=password --databases=db1 --tables=c
DATABASE TABLE   CHUNK HOST         ENGINE      COUNT         CHECKSUM TIME WAIT STAT  LAG
db1      c           0 192.168.X.XX InnoDB     215169         d1d52a31    2    0 NULL NULL
mk-table-checksum --algorithm=BIT_XOR h=localhost,u=user,p=password --databases=db1 --tables=c
DATABASE TABLE   CHUNK HOST      ENGINE      COUNT         CHECKSUM TIME WAIT STAT  LAG
db1      c           0 localhost InnoDB     215169         91e7f182    0    0 NULL NULL

It was rather crazy until I reviewed the mysqldump settings I was using, and I realized I was using –no-set-names.

So just what does this option remove. Here is a diff of mysqldump with and without.

5a6,10
>
> /*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
> /*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
> /*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
> /*!40101 SET NAMES utf8 */;
153a159,161
> /*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
> /*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
> /*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
156c164

As you can see it executes a SET NAMES utf8. The problem here is I’m exporting a table, and it is DEFAULT CHARSET=latin1, and no columns are defined as utf8.

I’m not expert in character sets, but this strikes me as strange, and a problem that remains unresolved to my satisfaction, resolved, but not to my comfort level.